Two dielectric or insulating materials commonly used in the fabrication of integrated circuitry are silicon dioxide and silicon nitride. These materials can be used alone, in combination with each other, and/or in combination with other materials, including property modifying dopants. Another common material utilized in semiconductor processing is silicon, for example in amorphous, monocrystalline and polycrystalline forms. Such material can be conductively doped with conductivity modifying impurities, for example to provide p-type electrical conduction or n-type electrical conduction.
In certain instances of integrated circuitry fabrication, a substrate in process might have outwardly exposed surfaces of different compositions. For example, any combination of silicon dioxide comprising, silicon-nitrogen bond comprising and silicon comprising materials might be outwardly exposed at the same time at some point during fabrication of the circuitry.